This invention relates to portable heavy duty tapping apparatus; and more particularly to such apparatus including a compact, lightweight, lead screw tapping tool unit with integrally attached hydraulic motor, powered by a remote hydraulic power unit.
An object of this invention is to provide improved tapping apparatus for heavy duty tapping operations, which includes a compact lightweight tool unit with integrally attached hydraulic motor, the tool unit being powered from a remote hydraulic power unit.
Another object of this invention is to provide such apparatus which is designed for ready portability and for ready set up at a job site location.
A further object of this invention is to provide such apparatus where the hydraulic motor is a high speed, low torque motor with internal gearing, for direct drive of the tool unit tapping spindle.
Still another object of this invention is to provide such apparatus, including a heavy duty high torque tapping tool unit, which is simple in construction and economic to manufacture.
A still further object of this invention is to provide such apparatus including a tool unit with a lead screw feed of the tap, and which is designed to prevent more than minimal damage to the tool unit in the event of control failure.
Another object of this invention is to provide such apparatus including a compact lightweight tool unit capable of tapping holes up to two inches in diameter.
A further object of this invention is to provide such apparatus including a tool unit adapted for use with a multiple tap head.
Still another object of this invention is to provide such apparatus including a lead screw tool unit designed for ready changeability of the lead screw spindle and lead nut assembly for adapting the tool for use with taps of different leads.
These objects are accomplished in apparatus wherein the tool unit comprises broadly an elongated housing, including an elongated body having a motor end and a spindle end, with ths housing body having external means for indexing the housing relative to a supporting jig or fixture. A reversible hydraulic motor is mounted at the body motor end, with its drive shaft extending axially into the body; and a lead nut is nonrotatably mounted at the spindle end of the body. A spindle has a lead screw intermediate its ends for coaction with the lead nut, has means for mounting the tap at its outer end, and has spline means at its inner end. The motor shaft includes drive spline means for coupling with the spindle spline means; and the motor drive spline means and the lead nut support the spindle for rotation and for longitudinal movement relative to the housing. The housing has means defining an elongated guideway extending parallel to the rotational axis of the spindle; and a control carriage is supported in the housing guideway for rectilinear movement therealong. Coupling means couples the control carriage to the spindle for simultaneous longitudinal movement. A reversing control device and a stop control device are mounted in longitudinally spaced relation on the housing; and the control carriage carries adjustable actuators for engaging and actuating these reversing and stop control devices.
More particularly, the spline drive means are designed for runout disengagement, before the spindle and control carriage reach the limits of feed movement relative to the housing. The lead nut is designed for demounting from the housing with minimal damage, in the event of excessive force urging said lead nut out of said housing.
The novel features and the advantages of the invention, as well as additional objects thereof, will be understood more fully from the following description when read in connection with the accompanying drawings.